Jack



J. C. KOPF.

JACK. APPLICATION FILED FEB- 18. I921.

1,397,871 Patented Nov. 22,1921.

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JACK.

APPLICATION FILED FEB. 18, 1921.

1,397,871 I Patented Nov. 22, 1921.

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1,397,871 Patentd Nov. 22, 1921.

3 SHEETS-SHE 2O '22 5mm m attoz-wcg i UNITED STATES PATENT OFFICE.

JOHN C. KOPF, OF BELLEVUE BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE DUFFMANUFACTURING COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

Specification of Letters Patent.

Patented Nov. 22, 1921.

Application filed February 18, 1921. Serial No. 445,981.

To all whom it may concern Be it known that I, JOHN C. Korr, a citizenof the United States, and resident of the borough of Bellcvue, in thecounty of Allegheny and State of Pennsylvania, have invented a new anduseful Jack, of which the following is a specification.

This invention relates to jacks, and more particularly to track jacks ofsurfacing jacks. These jacks are used to raise the rails, or the railsand ties, and have customarily been ratchet jacks, having holding andlifting pawls, the pawls engaging either directly with teeth on thejack-bar, or with a circular ratchet geared through a pinion with thebar. The object of this invention is to provide a jack more particularlyof this class, though not a ratchet jack in the ordinary sense, havingstraight lift on the jackbar and consequent efliciency, affording exactadjustment in lifting, having great lever advantage, and being capableof operating satisfactorily at an inclination, and further presentingthe important feature of being capable of being dropped instantly andsurely in case of an approaching tram. To this end the inventioncomprises a novel combination possessing all the advantages of thegeared ratchet jack, with greater strength, compactness, efficiency, andreliability in lifting and holding, and greater certainty and dispatchin dropplng.

In the accompanying drawings forming a part hereof:

Figure 1 is a side elevation of a jack embodying the invention, the gearcase being shown in vertical section with interior parts in elevation;

Fig. 2 is a rear elevation;

Fig. 3 is a vertical section on the line 33 of Fig. 1; and

Fig. 4 is a vertical section on the line l-i of Fig. 1.

The jack has a stand 1, and a jack-bar 2 slidable vertically in thestand and provided along one side with rack-teeth 3. On the lower end ofthe bar is a tone 4, and at its upper end a head 5.

transverse operating shaft 6 is journaled in bearings in the frame andhas fixed thereon av pinion 7 which meshes with the rack-teeth. One endof this shaft projects from the frame, and bears a ratchet wheel orserrated wheel 8, which is driven by a pivoted actuating pawl 9 in anoscillatory lever socket 10 swung on the shaft. The pawl is pressedagainst the ratchet by a spring plunger 12, which will also hold thepawl out of engagement with the wheel when the pawl is manually thrownto this position in readiness for lowering.

11 another portion of the shaft, within a case 15 formed on the frame,is a worm wheel 16; and meshing with said wheel is a worm 17 on a shaft18. The latter shaft is journaled at one end in a bearing in the fixedframe and at the other end in a bearing in a bonnet 19 which is screwedinto a large opening in the case. The worm and the worm wheel are ofsteep pitch, so that the worm wheel is capable of rotating the wormunder the action of the load. The end-thrust due to the load urges theworm to the right in Fig. 1, and in so doing compacts a suitable numberof loose flat friction disks 20, 21 against each other and against asolid abutment on the frame, whereby suflicient friction is produced byany load to hold it against descent. The said disks encircle the portionof the worm-shaft within the bonnet, the disks 20 being keyed to theshaft, and the disks 21 alternating therewith being adapted to be heldagainst rotation, preferably by being anchored to the frame, by havingexternal notches which engage ribs 22 in the bonnet. The abutment isafforded by a plug 23 screwed into the outer end of the bonnet andhaving an annular rib 24 to sustain the outermost disk. The thrust istransmitted from the worm to the innermost disk by a sleeve 25, servingalso as a bearing bushing in the inner end of the bonnet.

Manual means are provided for releasing the holding device. For thispurpose a screw 26 is shown passing through a screw threaded opening inthe plug 23, in line with the worm-shaft, the end of the screw beingadapted to bear upon the end of the shaft within a cavity 27 in the plugthrough an interposed thrust element 28. A handle 29 on this screwenables it to be readily turned and thereby moved endwise. In this way,a quick movement in one direction is sufiicient to back off the shaftand worm slightly and reduce or remove the friction between the disks sothat the loaded jack-bar will drop, driving the gearing idly. Moving thescrew in the opposite direction restores the holding device to conditionfor holding.

, critical moment.

The effort required to cause the jack-bar to drop is thus very slightand there is no possibility of the jack becoming caught at a Graduallowering can also be effected by proper manipulation of the screwhandle.

What I claim as new is: V

1. A jack comprising the combination of a stand, a rack-toothedjack-bar, an operating shaft journaled in the stand bearing a pinionmeshing the teeth of the jaclcbar, ratchetlever operating means on theouter end of said shaft, a worm-wheel also on the shaft, a worm meshingwith the worm-wheel and adapted to be driven thereby, a frictionalholding device applied by the endthrust of said worm, and means forreleasing the holding device.

2. A jack comprising the combination of a stand, a rack-toothedjack-bar, an operating shaft journaled in the stand bearing a pinionmeshing the teeth of the jack-bar, ratchet-lever operating means on theouter end of said shaft, a wornrwheel also on the shaft, a worm meshingwith the wormwheel and adapted to be driven thereby, a frictionalholding device applied by the endthrust of said worm, and amanually-operated screw for relieving the pressure on said device.

3. A jack comprising the combination of stand, a rack-toothed jack-bar,an operating shaft journaled in the stand bearing a pinion meshing theteeth of the jaclebar, ratchet-lever operating meanson the outer end ofsaid shaft, a worm-wheel, also on the shaft,a worm meshing with andadapted to be driven by the worm-wheel and having an endwise-movableshaft, a bonnet receiving one end portion of said worm-shaft, a plug inthe outer portion of the bonnet, a holding device comprising frictiondisks in the bonnet at the inner side of the plug,alternately connectedto the bonnet and to the shaft, and an axial manually-operated screw insaid plug to bear upon the end of the shaft.

, JOHN C. KOPF.

